Here lay a Viking fortress -
One of Denmark's five ring fortresses

Odense's Viking fortress, Nonnebakken, is no more, but its location is still just visible where the Oddfellow lodge now stands.

Nonnebakken was one of the five ring fortresses of Trelleborg type, named after the best preserved, Trelleborg near Slagelse. Odense's Viking fortress was about 120 metres in diameter. In 1908, the mill race^* of Munke Mølle was filled in using material from the fortress, the street "Filosofgangen" was created and Nonnebakken was then removed.

* The channel carrying water to the mill wheel. The water is led from the mill pond through the mill race to the mill wheel.

It was very probably King Harold Bluetooth who had the fortresses built around AD 980. On the Jelling Stone, Harold states that he won all of Denmark. He therefore needed these power bases in order to control his newly-won kingdom. The threat from the German emperor Otto II would certainly also have speeded up construction of the ring fortresses.

In the school yard at Giersings Realskole, a row of paving stones can be seen which were laid to mark the inner and outer foot of the earthworks surrounding the fortress.

Nuns on the hill

The convent is thought to have been built on the fortress site in the